获取系统时间差值

        SimpleDateFormat dfs = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        long  between = 0;
        try {
            java.util.Date begin = dfs.parse("2020-02-19 18:09:38.749");
            java.util.Date end = dfs.parse("2020-02-19 18:11:38.572");
            between = (end.getTime() - begin.getTime());
            // 得到两者的毫秒数
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        long day = between / (24 * 60 * 60 * 1000);
        long hour = (between / (60 * 60 * 1000) - day * 24);
        long min = ((between / (60 * 1000)) - day * 24 * 60 - hour * 60);
        long s = (between / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60);
        long ms = (between - day * 24 * 60 * 60 * 1000 - hour * 60 * 60 * 1000
                - min * 60 * 1000 - s * 1000);
        System.out.println(day + "天" + hour + "小时" + min + "分" + s + "秒" + ms                + "毫秒");
    }